Material Extrusion Additive Manufacturing Systems

2020 ◽  
pp. 40-51
Author(s):  
David A. Prawel
Keyword(s):  
Additive Manufacturing ◽  
Manufacturing Systems ◽  
Material Extrusion

scholarly journals Design for additive manufacturing - effects of part orientation, printer selection, and infill density on mechanical properties and production cost

2020 ◽  
Author(s):  
Ruiqi Chen ◽  
Liseli Baich ◽  
James Lauer ◽  
Debbie G. Senesky ◽  
Guha Manogharan
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Production Cost ◽  
Manufacturing Systems ◽  
Cost Savings ◽  
Beam Theory ◽  
Mechanical Stiffness ◽  
Entry Level ◽  
Material Extrusion ◽  
Part Orientation

This original work investigates the influence of infill design, printer selection, and part orientation on the mechanical properties and production cost of parts fabricated using material extrusion additive manufacturing systems. Flexural test specimens are fabricated in both production-grade (Fortus 250mc) and entry-level (MakerBot Replicator 2X) material extrusion systems with varying infill densities (1 mm to 10 mm spacing between rasters). In addition, solid infill specimens are printed in three orientations to establish baseline mechanical stiffness and strength. Finite element simulations and a simplified analytical model based on Euler-Bernoulli beam theory are developed. Results show reasonable agreement between analytical, simulation, and experimental results; 10-20% and 10-40% deviation for production-grade and entry-level specimens specimens, respectively. There is a 40% reduction in stiffness and strength between the solid XY specimen and 1 mm infill specimen. As infill density is further decreased, stiffness and strength asymptotically reduces by 60-70% when compared to solid specimens. This effect is more pronounced in specimens fabricated using entry-level printers, which indicates that printer selection plays a role in printing highly sparse parts. Cost analysis suggests that up to 40% savings can be achieved with highly sparse structures. However, for structural parts, it is recommended that parts be printed with solid infill and with the loading direction aligned in the XY plane to achieve high stiffness, high strength, and reasonable cost. Findings from this study show that there is minimal cost savings but high reduction in mechanical stiffness and strength when sparse infills are used in both production-grade and entry-level printers. Hence, it is recommended that solid infill should be used in all regions of parts that carry significant mechanical stress and sparse infill be used solely to support internal geometries and overhangs.

scholarly journals MODEL-BASED DESIGN OF AM COMPONENTS TO ENABLE DECENTRALIZED DIGITAL MANUFACTURING SYSTEMS

2021 ◽  
Vol 1 ◽  
pp. 2127-2136
Author(s):  
Olivia Borgue ◽  
John Stavridis ◽  
Tomas Vannucci ◽  
Panagiotis Stavropoulos ◽  
Harry Bikas ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Manufacturing Systems ◽  
Production Systems ◽  
Data Generation ◽  
Production Networks ◽  
Model Based ◽  
Manufacturing Technologies ◽  
Am Processes ◽  
Final Consumer

AbstractAdditive manufacturing (AM) is a versatile technology that could add flexibility in manufacturing processes, whether implemented alone or along other technologies. This technology enables on-demand production and decentralized production networks, as production facilities can be located around the world to manufacture products closer to the final consumer (decentralized manufacturing). However, the wide adoption of additive manufacturing technologies is hindered by the lack of experience on its implementation, the lack of repeatability among different manufacturers and a lack of integrated production systems. The later, hinders the traceability and quality assurance of printed components and limits the understanding and data generation of the AM processes and parameters. In this article, a design strategy is proposed to integrate the different phases of the development process into a model-based design platform for decentralized manufacturing. This platform is aimed at facilitating data traceability and product repeatability among different AM machines. The strategy is illustrated with a case study where a car steering knuckle is manufactured in three different facilities in Sweden and Italy.

Analysis for understanding and standardization of additive manufacturing processes

2021 ◽  
Author(s):  
Alexander Matschinski ◽  
Tim Osswald ◽  
Klaus Drechsler
Keyword(s):  
Additive Manufacturing ◽  
High Performance ◽  
Manufacturing Systems ◽  
Polymer Melt ◽  
Thermal Shrinkage ◽  
Target Component ◽  
Associated Functions ◽  
Cooling Mechanism ◽  
Characteristic Values ◽  
As Stress

The market segment of additive manufacturing is showing an annual growth of more than ten percent, with extrusion-based processes being the larger segment of the market. The scope of use is limited to secondary structures. Equipment manufacturers try to guarantee constant material characteristics by closed systems. The characteristic values are up to 50% below the ones from injection molding. The processing of high-performance polymers with reinforcing fibers is an additional challenge. Further development requires an opening of the material and manufacturing systems. The guidelines and standardization for this are still missing. For this reason, a functional analysis (FA) according to TRIZ ("theory of the resolution of invention-related tasks") is performed within this study. This identifies the undesired functions and quantifies their coupling with process components and parameters. In the FA, the manufactured part is the target component in order to address its quality. This way the FA identifies five undesirable functions in the process. These are: deform, cool, weaken, swell and shape. For hightemperature thermoplastics, thermal shrinkage is the primary cause of geometric tolerance. Therefore, the deformation is largely dependent on the cooling mechanism. For a detailed analysis, the polymer melt is further disassembled. The results are six sub-components. The weakening is mainly due to the physical phase of the voids, which exists during the entire processing. The breakdown comprises physical fields such as stress, temperature and flow. These determine the output properties as well as the bonding between the layers. The associated functions are the swelling and shaping. In order to generate broadly applicable standardizations, research questions for further investigation are derived from this study.

Fractal Pattern Recognition of Image Profiles for Manufacturing Process Monitoring and Control

2018 ◽  
Author(s):  
Farhad Imani ◽  
Bing Yao ◽  
Ruimin Chen ◽  
Prahalada Rao ◽  
Hui Yang
Keyword(s):  
Additive Manufacturing ◽  
Process Monitoring ◽  
Manufacturing Process ◽  
Manufacturing Systems ◽  
Experimental Studies ◽  
Precision Machining ◽  
Monitoring And Control ◽  
Process Monitoring And Control ◽  
Ultra Precision ◽  
And Control

Nowadays manufacturing industry faces increasing demands to customize products according to personal needs. This trend leads to a proliferation of complex product designs. To cope with this complexity, manufacturing systems are equipped with advanced sensing capabilities. However, traditional statistical process control methods are not concerned with the stream of in-process imaging data. Also, very little has been done to investigate nonlinearity, irregularity, and inhomogeneity in image stream collected from manufacturing processes. This paper presents the multifractal spectrum and lacunarity measures to characterize irregular and inhomogeneous patterns of image profiles, as well as detect the hidden dynamics of the underlying manufacturing process. Experimental studies show that the proposed method not only effectively characterizes the surface finishes for quality control of ultra-precision machining but also provides an effective model to link process parameters with fractal characteristics of in-process images acquired from additive manufacturing. This, in turn, will allow a swift response to processes changes and consequently reduce the number of defective products. The proposed fractal method has strong potentials to be applied for process monitoring and control in a variety of domains such as ultra-precision machining, additive manufacturing, and biomanufacturing.

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